Hellschreiber – German for ‘light pen’ – was developed in the 20s as a way to transmit text in a way that was much more robust than the teletypes of the time. These devices were used to great effect by the Germans in WWII, and later became popular with wire services and was used until the 80s. The fax machine then happened, and no one really cared about Hellschreiber, save for a few plucky amateur radio enthusiasts.
In the early 90s, a few of these amateur radio enthusiasts realized they could use their personal computers to communicate with this extremely simple protocol that’s also very resilient against interference and weak radio links. [Danjovic] is following in their footsteps by decoding Hellschreiber on an old ZX Spectrum clone.
[Danjovic] tested his code with the sound sample found in the Hallschreiber wiki article and some text generated by Fldigi. Everything works beautifully, an [Dan] can even change the intensity of the text with the volume control – a very useful feature should the HellZXchreiber ever make it out into the field.
Source and image files available for all you strange Speccy fans. Everyone else can check out the videos below.
[Tim Linhart] wanted to do something different for this Swedish music festival — so he decided to carve all the instruments by hand, out of ice.
The festival consists of seven bands playing very different musical styles, with over 40 concerts occurring during the festival. [Tim Linhart] has painstakingly carved each instrument from violins to cellos out of individual sheets of ice. He adds strings and fret-boards to complete each piece, and if the temperature goes above zero it’s game over. The concerts are held in a building made of ice to make sure this doesn’t happen.
And since they are built out of layers — he’s also thrown in some RGB LEDs to give the instruments a bit more pizzazz. They actually sound pretty good too!
With the launch of hackaday.io, our project hosting site, we’ve seen quite a bit of interesting hacks flowing in. While we feature some of our favorite projects on the blog, we’ve decided it’s time to start a regular recap of what’s going on in the Hackaday Projects community. We call it The Hacklet, and the first issue is now available.
This installment starts off with information on our Sci-fi Contest and improvements to the Hackaday Projects site. We talk a bit about the various projects relating to the Mooltipass password manager being developed on Hackaday. The Mooltipass has its own project page, but there’s also separate projects for the low level firmware being developed. Next we look at a pair of NFC rings for unlocking Android devices, and finish off with advice on soldering tiny packages.
Check it out and let us know what you think. Our goal is to summarize some of the neat things going on in the community, and we’re always happy to get constructive feedback from the community itself. Or you can flame us… whichever you prefer.
Once you’ve dialed in your 3D printer calibration settings, you enter the phase of printer ownership where you’re eager to show off what you can make, and you’re sure to impress with [pjensen's] 3d printed cryptex spinning around in your hands.
If you’re a regular reader of our 3D Printering column, then the behind-the-scenes screengrabs should look familiar: [pjensen] used Autodesk Inventor to sculpt the shapes, staring with the cryptex’s individual rings. After embossing the alphabet across each ring, [pjensen] adds slots into the inner loops for pins to slide through. An outer chamber holds the rings in place and prohibits access to the interior chamber, which is held in place on both sides by an end cap.
Lining up the rings to spell the correct word allows the inner chamber to slide free of the whole assembly, revealing whatever goodies may lie inside. You can follow [pjensen's] step-by-step guide to build your own cryptex, or just download his model and start printing.
The Hackaday writers and readers are currently working hand-in-hand on an offline password keeper, the Mooltipass. A few days ago we presented Olivier’s design front PCB without even showing the rest of his creation (which was quite rude of us…). We also asked our readers for input on how we should design the front panel. In this new article we will therefore show you how the different pieces fit together in this very first (non-final) prototype… follow us after the break!
As MMA continues to grow in popularity, the competition is getting tougher. There’s always someone else out there who’s training harder and longer than you are. So how do you get the advantage over your competitors? More push-ups? Sit-ups? Eat more vegetables? What about installing custom 2 by 1 inch, 5 gram PCB’s armed with an ATmega32U4, a MPU-6050 6 axis accelerometer and an RN-41 Bluetooth module into each of your gloves? Now that’s what we’re talking about.
[Vincent] and [Jooyoung] of Cornell joined their classmates in turning out another cool piece of electrical engineering. Fight Coach records data from the fighter’s gloves so that it can not only be analyzed to improve performance, but also interact with the fighter in real-time. Though not quite as immersive as some fighter training techniques we’ve seen, Fight Coach might just give a fighter a slight edge in the ring.
Fight Coach offers 3 modes of training: Defense mode, Damage mode and Free-Training mode. As usual with Cornell projects, all code, schematics and a wealth of information on the project is just a click away. And stick around after the break for a video demonstration of Fight Coach.
Have you ever heard of a Cryotron Computer before? Of course not. Silicon killed the radio star: this is a story of competing technologies back in the day. The hand above holds the two competitors, the bulkiest one is obviously the vacuum tube, and the three-legged device is what became a household name. But to the right of that tube is another technological marvel that can also be combined into computing machines: the cryotron.
[Dudley Allen Buck] and his contributions to early computing are a tale of the possible alternate universe that could have been cryotrons instead of silicon transistors. Early on we find that the theory points to exotic superconductive materials, but we were delighted to find that in the conception and testing stages [Buck] was hacking. He made his first experimental electronic switches using dissimilar metals and dunking them in liquid helium. The devices were copper wire wrapped around a tantalum wire. The tantalum is the circuit path, the copper wire acts as the switch via a magnetic field that alters the resistance of the tantalum.
The name comes from the low temperature bath necessary to make the switches work properly. Miniaturization was the key as it always is; the example above is a relatively small example of the wire-wound version of the Cryotron, but the end goal was a process very familiar to us today. [Buck] was searching for the thin film fabrication techniques that would let him shoe horn 75,000 or more into one single computing platform. Guess who came knocking on his door during this period of his career? The NSA. The story gets even more interesting from there, but lest we rewrite the article we leave you with this: the technology may beat out silicon in the end. Currently it’s one of the cool kids on the block for those companies racing to the quantum computing finish line.
Retrotechtacular is a weekly column featuring hacks, technology, and kitsch from ages of yore. Help keep it fresh by sending in your ideas for future installments.